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IMAGINATION   AND  IDEALISM  IN 
THE  MEDICAL  SCIENCES 


CHRISTIAN    A.    HERTER,    M.D. 

Professor  of  Pharmacology,  Columbia  University 
NEW  YORK    CITY 


An   Address   Delivered  to  the  College  of   Physicians   and 

Surgeons,  Columbia  University,  Sept.  23,  1909, 

at  the  Opening  of  the  Medical  School 


PBM8  "i    jiii.   Ambbicah    (Medical  Association 

.".::.",  I)i;ahiiuu.n  Avio  i;k 

Chicago 


IMAGINATION  AND  IDEALISM  IN  THE 
MEDICAL  SCIENCES* 


CHRISTIAN  A.  HERTER,  M.D. 

Professor  of  Pharmacology,  Columbia  University 
NEW  YORK 


The  presidential  invitation  in  response  to  which  I  am 
about  to  address  yon  to-day  was  welcome  to  me  because 
it  offered  a  rare  chance  to  express  some  views  of  medical 
progress  which  I  think  are  too  seldom  presented  to  the 
student.  I  have  in  mind  the  influence  of  imagination 
and  idealism  on  the  growth  of  medical  discovery.  Viv- 
idly recalling,  as  I  do,  the  experiences  of  my  own  stu- 
dent days,  more  than  a  quarter  century  past,  I  fancy 
you  as  coming  to  the  acquisition  of  the  myriad  facts  of 
medicine  with  little  to  tell  you  of  the  intellectual  forces 
and  historical  sequences  by  which  those  facts  have 
emerged.  If  this  surmise  be  correct,  it  follows  that  you 
incline  to  take  a  static  rather  than  a  dynamic  view  of 
the  nature  of  scientific  medicine,  in  the  sense  that  you 
regard  medical  lore  as  something  much  more  fixed  than 
is  actually  the  case.  In  reality,  our  science  is  fortunately 
plastic,  constantly  subject  to  revision  of  its  facts,  and 
r  ready  to  welcome  new  interpretations  of  old  facts 
:i-  well  as  new  discoveries,  both  great  and  small.    This 

*  An   ndrlioHH   delivered   at   the   College  of   Physicians   and   Sur- 
ilumbla    University,   Sept.   2'.',,   1!)09,  at  the  opening  of  the 
Medical   BCQOOl. 

3 


very  plasticity  it  is  that  makes  progress  attainable  and 
fascinates  our  minds.  But  our  text-books  and  our  lec- 
tures are  necessarily  conservative  and  dispose  us  strongly 
to  the  notion  of  fixity  of  facts,  making  our  minds 
statical  in  conception.  I  would  like  to  dispel,  in  a 
measure,  this  retarding  conception  by  telling  you  some- 
thing of  the  ways  in  which  gifted  and  trained  minds 
have  enriched  the  medical  sciences  by  significant  dis- 
coveries. And  of  the  qualities  underlying  such  dis- 
coveries I  would  emphasize  especially  the  role  of  imagi- 
nation and  idealism. 

The  fine  humanitarian  aim  of  medicine  always  has 
been  and  always  will  be  one  of  the  features  that  make 
men  love  to  practice  the  art.  And  the  idealism  that 
delights  in  the  relief  of  human  suffering  and  disability 
will  remain  alive  so  long  as  the  healing  art  itself.  But 
we  must  not  blind  ourselves  to  the  fact  that  this  very 
attitude  of  eager  desire  to  help  our  fellows  in  distress  is 
a  source  of  weakness  as  well  as  a  pillar  of  strength.  For 
he  who  would  answer  the  calls  of  the  sick  must  resort 
to  direct  methods  and  must  generally  tread  the  paths  of 
the  obvious.  He  has  not  time  to  turn  aside  to  the  indi- 
rect ways  of  winning  the  citadel,  nor,  indeed,  is  he 
likely  to  be  in  that  frame  of  mind  which  urges  to  such 
an  approach;  he  is  preoccupied  with  the  crying  needs  of 
the  suffering  or  dying  man  committed  to  his  charge. 
Yet  it  is  growing  every  day  clearer  that  the  progress  of 
the  medical  sciences  depends  in  a  remarkable  degree  on 
discoveries  made  by  indirect  methods — that  is,  by  meth- 
ods not  looking  to  the  immediate  relief  of  disease. 

These  discoveries  are  made  chiefly  by  men  who,  while 
in  deep  sympathy  with  the  humanitarian  aims  of  medi- 
cine, nevertheless  find  time  to  turn  aside  to  studies  and 
experiments  from  which  the  active  practitioners  are,  in 


general,  excluded,  by  the  circumstances  of  their  lives  and 
the  intensely  practical  nature  of  their  vocation.  There 
was  a  time  when  the  alert  physician  or  surgeon,  with 
little  or  no  training  in  the  experimental  method,  might 
make  important  contributions  to  knowledge  by  following 
rather  evident  suggestions  derived  from  the  study  of 
patients.  The  Romans,  operating  for  stone  in  the  blad- 
der; Pare,  using  the  ligature  to  check  hemorrhage  on 
the  field  of  battle;  McDowell,  successfully  removing 
ovarian  tumors,  give  us  examples  of  great  advances  along 
rather  obvious  lines  of  development.  To-day  the  chances 
for  significant  progress  in  such  evident  directions, 
although  not  exhausted,  are  far  less  frequent.  The 
golden  nuggets  at  or  near  the  surface  of  things  have 
been  for  the  greater  part  discovered,  it  seems  safe  to  say. 
We  must  dig  deeper  to  find  new  ones  of  equal  value,  and 
we  must  often  dig  circuitously,  with  mere  hints  for 
guides.  Our  most  effective  tools  are  to  be  found  in  the 
experimental  laboratory,  where  the  fundamental  sciences, 
physics  and  chemistry,  come  to  the  aid  of  physiology, 
biology,  pathology  and  psj-chology.  I  should  like  to  tell 
you  of  some  of  the  many  instances  in  which  these 
sciences  have  come  to  the  succor  of  medicine  and  have 
brought  her  riches  of  knowledge  unattainable  had  she 
been  limited  to  resources  belonging  to  the  accumulated 
experience  which  makes  up  the  accepted  material  of 
medical  teaching.  If  I  incidentally  say  something  of  the 
personality  of  the  men  who  have  been  the  living  instru- 
ments of  this  progress,  it  is  in  order  to  give  you  occa- 
sional glimpses  into  the  workings  of  some  of  the  most 
original  and  productive  of  minds. 

I  like  to  think  of  medicine  in  our  day  as  an  ever- 
broadening  and  deepening  river,  fed  by  the  limpid 
-tream.-  of  pure  science.     The  river  at  its  borders  has  its 


eddies  and  currents,  expressive  of  certain  doubts  and 
errors  that  fringe  all  progress;  but  it  makes  continuous 
advances  on  the  way  to  the  ocean  of  its  destiny.  Very 
gradual  has  been  the  progress  of  its  widening  and  deep- 
ening, for  it  is  a  product  of  human  ingenuity  and  arti- 
fice, and  only  skilled  engineers  could  direct  the  isolated 
currents  of  science  into  the  somewhat  sluggish  stream  of 
medical  utility.  The  names  of  some  of  the  greatest  of 
these  engineers  are  familiar  to  you — Vesalius,  Harvey, 
Malpighi,  John  Hunter,  Claude  Bernard,  Helmholtz, 
Virchow,  Metchnikoff,  Pasteur,  Lister,  Koch,  Behring, 
Ehrlich,  Emil  Fischer,  Weigert,  Wright,  Theobald 
Smith,  Flexner.  Different  as  have  been  the  achieve- 
ments of  these  men,  there  are  some  qualities  of  mind 
and  of  heart  which  nearly  all  of  them  have  shown  in 
ample  measure,  and  of  such  qualities  none  are  more 
evident  than  imagination,  or  play  of  fancy,  and  personal 
idealism,  using  the  latter  term  to  mean  a  readiness  to 
make  sacrifices  for  the  sake  of  lofty  achievement.  And 
I  think  we  are  quite  safe  in  making  the  generalization 
that  the  discoveries  for  which  we  hold  these  thinkers  in 
honor  would  have  been  impossible  but  for  the  exercise 
of  these  qualities.  If  this  be  true,  the  fact  furnishes  us 
with  a  clue  to  present  tendencies  in  medicine  and  shows 
us  to  what  sorts  of  gifts  we  have  to  look  for  the  signifi- 
cant advances  of  the  future.  I,  therefore,  hope  to  make 
good  my  generalizations  by  a  series  of  examples. 

If  we  look  over  any  list  of  the  names  of  the  makers 
of  modern  medicine,  we  shall  find  that  they  may  be 
classed  in  two  main  and  definite  groups,  according  to  the 
intellectual  trend  for  which  they  stand.  One  group 
holds  the  men  who  look  at  the  problems  of  medical 
science  largely  from  the  standpoint  of  structure  and 
arrangement.    They  have  the  instincts  and  interests  of 


the  morphologists.  They  represent  anatomy,  embryol- 
ogy, pathological  anatomy  and  histology.  They  have 
usually  been  men  of  powerful  and  logical  minds,  craving 
the  positive,  the  definite  and  the  attainable,  either  shun- 
ning somewhat  the  speculative  aspects  of  science,  or 
moving  uncomfortably  in  the  midst  of  ill-defined  or 
challengeable  facts.  In  this  list  belong  Vesalius,  von 
Baer,  Bichat,  Virchow  and  Weigert,  who  represent  with 
maximal  distinction  the  group  of  investigators  with 
dominant  morphological  tendencies. 

In  sharp  contrast  with  this  definite  type  stands  the 
second  group,  made  up  of  men  whose  interests  lie  in 
the  study  of  function,  rather  than  structure,  and  whose 
minds,  far  from  being  dismayed  by  the  speculative 
aspects  of  their  studies,  invite  such  speculation  so  long 
as  it  is  severely  controlled  by  frequent  appeals  to  facts 
won  by  experiment.  The  members  of  this  small  group 
are  dynamically  minded,  highly  imaginative,  delighting 
in  the  play  of  forces.  They  are  essentially  experimental- 
ists, and  their  thoughts  in  leisure  hours,  as  in  the  hours 
of  work,  turn  always  restlessly  and  uncontrollably  in 
the  same  direction — to  the  planning  of  new  experiments 
designed  to  answer  the  questions  uppermost  in  con- 
sciousness, questions  having  nearly  always  to  do  with  the 
phenomena  of  living  beings.  Claude  Bernard,  Helm- 
holtz,  Pasteur  and  Ehrlich  are  the  unexcelled  prototypes 
of  investigators  of  life-phenomena  in  medicine,  and  we 
shall  not  go  far  astray  if  we  fancy  them  as  spirits 
inspired  by 

"All  that  is  great  and  all  that  is  strange 
In  the  boundless  realm  of  unending  change." 

We  have  also,  I  think,  to  recognize  an  intermediate 
group  of  iivoni  investigatora  who,  while;  highly  trained 
in  :i  morphological  way,  have  shown  abo  a  deep  and 

7 


productive  interest  in  the  functional  aspects  of  organ- 
ized nature,  without,  however,  attaining  the  highest 
levels  of  achievement  in  thought  on  the  dynamical  side 
of  medical  research.  In  this  category  we  may  place 
Harvey,  Malpighi,  John  Hunter,  Johannes  Miiller, 
Cohnheim  and  Robert  Koch.  And  I  think  we  may 
safety  add  that  most  modern  investigators,  educated 
under  the  influence  of  the  strong  trend  to  physiological 
thought,  belong  in  this  intermediate  position. 

The  examples  of  medical  discovery  which  I  shall  first 
bring  to  your  notice  I  shall  select  from  the  first  and 
intermediate  groups  of  workers,  reserving  the  illustra- 
tions from  the  second  group  for  subsequent  considera- 
tion. 

The  first  great  morphologist  of  modern  times  is  Vesa- 
lius,  whose  claims  to  recognition  rest  not  merely  on  his 
masterly  and  precise  description  of  the  parts  of  the 
human  body,  but  also  on  his  abrupt  departure  from  the 
Galenic  traditions  and  teachings,  forced  on  him  by  the 
objectivity  and  sincerity  of  his  studies.  While  we  must 
regard  the  work  of  Vesalius  as  evidence  of  intellectual 
and  logical  power,  it  would  be  an  error  to  credit  him 
with  the  highest  type  of  imagination  or  with  elaborate 
esthetic  reactions.  The  self-willed,  clear-thinking  man 
won  his  triumphs  more  by  force  of  character  and 
unswerving  purpose  than  by  creative  intellect;  and  we 
see  this  type  of  worker  repeated  in  some  of  our  greatest 
modern  anatomists,  as  also  in  some  fields  in  which  the 
experimental  method  is  prominent. 

The  idealism  which  inspired  Vesalius  was  not  proof 
against  exasperations  and  discouragements  due  to  the 
hostility  of  the  Catholic  church  to  all  research  on  the 
human  body.     After  destroying  valuable  manuscripts 

8 


and  resigning  his  professorship,  the  great  anatomist 
attached  himself  to  the  court  of  the  Emperor  Charles  V 
and  afterward  to  that  of  Philip  II.  But  power  and  posi- 
tion and  wealth  did  not  repay  him  for  the  loss  of  intel- 
lectual freedom  which  such  associations  imposed,  and 
for  some  reason  he  left  Spain  to  visit  the  Holy  Land. 
It  is  said  that  the  pilgrimage  was  made  in  penance  for 
an  autopsy  performed  on  a  young  woman  not  quite 
dead;  and  Edith  Wharton  has  seized  on  the  story  to 
enrich  her  admirable  Browning-like  poem,  "Vesalius  in 
Zante" : 

The  girl  they  brought  me,  pinioned  hand  and  foot 

In  catalepsy — say  I  should  have  known 

That  trance  had  not  yet  darkened  into  death, 

And  held  my  scalpel.    Well,  suppose  I  knew? 

Sum  up  the  facts — her  life  against  her  death. 

Her  life?     The  scum  upon  the  pools  of  pleasure 

Breeds  such  by  thousands.     And  her  death?     Perchance 

The  obolus  to  appease  the  ferrying  Shade, 

And  waft  her  into  immortality. 

Think  what  she  purchased  with  that  one  heart-flutter 

That  whispered  its  deep  secret  to  my  blade! 

Ah,  no!     The  sin  I  sinned  was  mine,  not  theirs. 

Not  that  they  sent  me  forth  to  wash  away — 

None  of  their  tariffed  frailties,  but  a  deed 

So  far  beyond  their  grasp  of  good  or  ill 

That,  set  to  weigh   it  in  the  Church's  balance, 

Scarce  would  they  know  which  scale  to  cast  it  in. 

But  I,  I  know.     I  sinned  against  my  will, 

Myself,  my  soul,  the  God  within  the  breast; 

Cm  any  penance  w&ela  such  sacrilege? 

Bow   vividly  and  how  justly  these  verses  paint  the 

LOT86  that  came  from  abandonment  of  ideals,  when 

the   young   investigator,   not  yet  thirty   years   of   age, 

9 


exchanged  the  inner  satisfaction  of  legitimate  work  for 
the  prestige  of  courts ! 

But  Vesalius  in  that  short  span  of  work  had  founded 
anatomy,  and  Eustaehius  and  Fallopius,  his  successors, 
united  their  influence  with  his  (despite  some  disloyalties 
and  antagonisms)  to  establish  the  scientific  method  in 
this  branch  of  learning.  The  future  of  anatomy  in 
Europe  seemed  assured.  This  gain  in  scientific  method, 
initiated  by  Vesalius,  was  fixed  and  established  in  Eng- 
land by  the  spirited,  penetrating  and  imaginative  Wil- 
liam Harvey,  whose  monumental  work  proved  that  all 
the  blood  in  the  body  travels  in  a  circuit  impelled  by 
the  beating  of  the  heart.  That  a  hugely  skilled  anat- 
omist should  have  made  this  physiological  discovery  is 
significant  evidence  that  studies  in  structure  may  stimu- 
late a  labile  mind  to  serious  investigation  of  the  func- 
tional side  of  organic  nature.  Probably  the  work  which 
Harvey  did  with  his  master,  Fabricius,  at  Padua  in  the 
anatomy  of  the  vascular  system  stimulated  his  interest 
in  the  discovery  of  experimental  methods  which  should 
expose  the  true  uses  of  this  elaborate  mechanism.  And 
the  same  ingenuity  which  led  to  such  conspicuous  suc- 
cess in  physiological  research,  the  same  interest  in  the 
vital  phenomena,  caused  Harvey  to  ponder  and  study 
the  mysteries  of  development  in  the  chick,  the  deer  and 
other  mammals.  These  embryological  observations  are 
of  such  a  grade  of  excellence  that  some  of  the  greatest 
biologists  regard  them  as  superior  in  quality  to  the 
immortal  studies  of  the  circulation. 

The  lofty  intellect  of  Harvey  was  linked  with  a  gen- 
erous and  idealistic  nature.    His  portraits  show  a  forma- 

10 


tion  of  head  and  face  that  reminds  us  of  representations 
of  Shakespeare.  Like  Hunter  and  Darwin,  he  had  the 
virtue  of  being  extremely  slow  in  publishing.  He  for- 
gave his  man}'  antagonists,  notwithstanding  the  troubles 
they  brought  into  his  life.    He  says : 

I  would  not  charge  with  wilful  falsehood  any  one  who  was 
sincerely  anxious  for  truth,  nor  lay  it  to  any  one's  door  as  a 
crime  that  he  had  fallen  into  error.  I  am,  myself,  the  partisan 
of  truth  alone;  and  I  can  indeed  say  that  I  have  used  all  my 
endeavors,  bestowed  all  my  pains  on  an  attempt  to  produce 
something  that  should  be  agreeable  to  the  good,  profitable  to 
the  learned,  and  useful  to  letters. 

More  than  a  hundred  years  after  the  death  of  Harvey 
there  emerged  from  obscurity  a  Scotchman,  John  Hun- 
ter, of  such  power  and  versatility  as  to  make  him  a 
worthy  intellectual  successor  of  the  great  Englishman. 
We  may  take  him  as  our  second  example  of  an  investi- 
gator of  our  intermediate  group,  combining  the  interests 
of  morphologist  and  physiologist.  Of  his  works  as 
anatomist  and  surgeon  and  comparative  anatomist,  I 
shall  say  nothing  here.  The  wonderful  Hunterian 
Museum  of  London  is  a  peerless  monument  to  the  labors 
of  the  anatomist  and  surgeon.  But  it  does  not  espe- 
cially direct  our  thoughts  to  his  physiological  and  experi- 
mental way  of  thinking,  which  we  may  safely  consider 
his  strongest  claims  to  greatness.  One  example — a  cele- 
brated instance — will  illustrate  the  point  I  wish  to  make. 
It  was  in  Richmond  Park  that  Hunter  saw  the  deer 
irhose  growing  antlers  awakened  in  his  mind  a  singu- 
larly fruitful  physiological  question.  What  would  hap- 
pen if  he  shut  ofT  the  blood-supply  of  the  antler  on  one 

11 


side  by  tying  the  corresponding  carotid  artery  ?  Experi- 
ment showed  that  the  antler  lost  its  warmth  and  ceased 
to  grow;  but  for  a  short  time  only  was  there  this  check 
to  growth.  After  a  time  the  horn  warmed  again  and 
grew.  Had  he  failed  to  really  obstruct  the  blood  flow 
in  the  artery?  No.  Examination  showed  the  carotid 
to  have  been  securely  ligated.  Whence,  then,  came  the 
blood  essential  for  the  antler's  growth?  Through  the 
neighboring  arteries  that  had  grown  distended,  through 
what  we  now  call  the  collateral  circulation.  So  was  the 
fact  of  the  collateral  circulation  revealed.  The  thought- 
ful and  logical  mind  of  the  practical  surgeon  soon  found 
an  important  application  of  this  discovery  to  human 
pathology.  No  one  had  dared  to  treat  aneurism  by  liga- 
tion for  fear  of  causing  gangrene.  But  the  existence  of 
a  collateral  circulation  held  out  a  prospect  of  keeping 
the  parts  alive  despite  the  ligation  of  an  important 
artery.  The  first  trial  of  the  new  method  on  a  popliteal 
aneurism  was  successful,  and  the  Hunterian  operation, 
as  you  know  it  in  surgery  to-day,  came  into  assured  exist- 
ence. An  unimaginative  man  could  not  have  made  this 
discovery  in  this  manner.  Yet  Hunter  belongs  to  the 
logical,  independent,  matter-of-fact  type  with  fancy  well 
controlled,  rather  than  to  the  dreamers  and  poets  of 
science.  He  was  a  rough  diamond,  with  an  intensely 
objective  nature,  and  he  had  corresponding  limitations. 
He  is  said  to  have  rebelled  against  the  classical  teach- 
ings of  Oxford.  "Why,  they  wanted  me  to  study  Greek. 
They  wanted  to  make  an  old  woman  of  me!"  And 
when  twitted  with  his  lack  of  knowledge  of  the  "dead 
languages"  he  said  of  his  critic:     "I  could  teach  him 

12 


that  in  the  dead  bod}"  which  he  never  knew  in  any  lan- 
guage, living  or  dead.''*  The  idealism  of  Hunter  showed 
itself  in  devotion  to  work  and  in  fortitude  in  the  advers- 
ity of  ill  health. 

1  wish  now  to  invite  your  attention  to  our  second  type 
of  investigator — the  essentially  dynamical  or  physiologi- 
cal discoverer.  The  group,  as  I  see  it,  is  a  small  one.  It 
includes  Claude  Bernard,  Louis  Pasteur,  Hermann  von 
Helmholtz  and  Paul  Ehrlich. 

An  admirer  said  sententiously  of  Bernard:  "He  is 
not  merely  a  physiologist;  he  is  physiology  itself";  and 
the  saying  has  the  merit  of  reminding  us  of  the  breadth 
and  depth  and  originality  of  his  researches.  With  equal 
skill  he  worked  at  the  physical  and  chemical  bases  of 
physiology;  and  we  owe  to  him  our  knowledge  of  the 
glycogenic  function  of  the  liver,  the  enzymes  of  the 
pancreatic  juice,  the  vasomotor  system  of  nerves,  diabetes 
from  puncture  of  the  fourth  ventricle,  besides  many 
minor  discoveries  and  researches  and  a  masterly  correla- 
tion of  the  general  facts  of  animal  and  plant  life.  Ber- 
nard was  one  of  the  founders  of  modern  pharmacology. 
He  also  foreshadowed  in  a  singular  manner  and  under 
singular  circumstances  the  modern  conception  of  soluble 
ferments  in  micro-organisms,  a  view  which  unfortun- 
ately brought  him  into  an  unpleasant  antagonism  with 
his  life-long  friend,  Pasteur. 

The  research   that  most  fully  shows  the  controlled 

imagination  of  Bernard  is  that  which,  extending  over 

-.  culminated    in    the   discovery  of  the  glycogenic 

function  of  the  liver,  a  discovery  of  the  very  first  signifi- 

e  to  physiology  and  pathology.    We  know  the  steps 

16 


which,  led  him  to  this  discovery,  and  in  retracing  these 
steps  we  get  an  edifying  glimpse  of  the  workings  of 
Bernard's  fertile  mind.  His  ambition  was  to  follow  the 
three  great  classes  of  foodstuffs,  carbohydrates,  fats  and 
proteids,  through  the  organism.  He  soon  felt  the  neces- 
sity of  limiting  himself  to  the  fate  of  the  carbohydrates, 
which,  besides  seeming  relatively  simple  to  study,  espe- 
cially attracted  him  on  account  of  their  mysterious  rela- 
tion to  diabetes.  The  first  step  in  the  research  brought 
out  the  fact  that  cane-sugar,  when  acted  on  by  gastric 
juice,  undergoes  a  transformation  which  adapts  it  for 
absorption  and  utilization  by  the  tissues — namely,  a 
change  into  dextrose  (glucose).  He  knew  from  the 
experiments  of  Tiedemann  that  starch  is  changed  into 
dextrose  in  the  digestive  tract  before  absorption.  Ber- 
nard asked  himself  what  was  the  fate  of  this  dextrose. 
He  proposed  to  trace  the  course  of  the  sugar  from  the 
digestive  tract,  along  the  portal  vein  to  the  liver,  from 
the  liver  to  the  lungs  by  way  of  the  right  heart,  and 
finally  from  the  lungs  through  the  left  heart  to  the 
various  tissues.  His  idea  was  that  at  one  of  these  sta- 
tions the  dextrose  disappears,  is  destroyed  or  in  some 
manner  changed.  "If  I  am  able,"  said  he,  "to  suppress 
the  activity  of  this  station,  sugar  will  accumulate  in  the 
blood  and  a  condition  of  diabetes  will  be  brought 
about."  Here,  then,  was  a  highly  interesting  enterprise. 
The  first  thing  to  do  was  to  feed  a  dog  freely  on  carbo- 
hydrates, kill  it  at  the  height  of  digestion  and  examine 
the  blood  leaving  the  liver  by  the  hepatic  veins  to  see  if 
any  sugar  were  lost  in  the  liver.  Please  note  that  Ber- 
nard was  helped  in  this  search  for  sugar  in  the  blood  and 

14 


tissues  by  the  cupric  sulphate  test  for  dextrose,  just 
introduced  by  his  friend,  Barreswill — a  very  material 
help.  Sugar  was  found  in  abundance  in  the  blood  of  the 
hepatic  veins ;  therefore,  the  liver  was  not  the  looked-f or 
place  of  disappearance  of  dextrose.  "But  how  do  I 
know,"  thought  Bernard,  "that  the  sugar  which  I  thus 
find  in  the  hepatic  vein  is  the  same  sugar  as  that  which 
I  introduced  into  the  portal  blood  through  the  food?" 
To  get  an  answer,  Bernard  fed  a  dog  on  meat  only, 
knowing  by  experiment  that  no  dextrose  would  then  be 
present  either  in  the  digestive  tract  or  in  the  portal 
blood.  Then  he  examined  the  blood  of  the  hepatic  vein 
for  sugar.  Great  was  his  surprise  to  find  it  loaded  with 
dextrose.  His  keen  intelligence  at  once  drew  the  correct 
inference — that  the  liver  is  a  sugar-making  organ  and 
makes  sugar  out  of  something  which  is  not  sugar,  and, 
furthermore,  that  within  the  liver  lies  the  secret  of 
diabetes.  Bernard  now  made  a  variety  of  experiments  to 
test  the  correctness  of  his  inferences.  He  soon  found 
that  sugar  was  contained  in  a  simple  decoction  of  the 
liver  and  that  this  sugar  was  dextrose,  capable  of  fer- 
mentation and  responding  to  all  the  known  tests.  But 
Bernard  did  not  stop  here.  His  fancy  urged  him  to  seek 
the  substance  in  the  liver  from  which  the  sugar  is  pro- 
duced— the  "glycogenic  substance"  whose  existence  was 
inferred  from  experiment.  And  in  time  he  isolated  the 
substance  which  we  know  to-day  as  glycogen. 

Bere,  then,  was  a  great  triumph  of  the  experimental 
method  in  the  hands  of  an  imaginative,  critical  and 
highly  skilled  technical  worker.  The  completeness  with 
wlnVli  the  discovery  at  the  glycogenic  function  of  the 

15 


liver  was  worked  out  makes  it  a  model  of  physiological 
research  for  all  time.  Moreover,  the  facts  elicited  by 
Bernard  in  this  research  possess  a  very  broad  bearing. 
They  show  that  the  liver  has  a  function  as  important  as, 
but  far  less  obvious  than,  the  secretion  of  bile — the  first 
example  of  an  internal  secretion.  And  they  prove 
that  animals  as  well  as  plants  can  build  up  carbohydrate 
material — glycogen — by  means  of  their  own  tissues. 
Finally  Bernard  very  clearly  showed  that,  while  the 
production  of  glycogen  from  sugar  is  a  vital  act,  in  the 
sense  of  occurring  only  under  conditions  of  life,  the 
converse  process,  namely,  the  formation  of  sugar  from 
glycogen,  is  independent  of  living  tissues  and  may  occur 
as  the  result  of  the  action  of  a  ferment  in  the  blood. 
As  Sir  Michael  Foster  said  most  aptly : 

It  is  in  the  putting  forth  of  the  hypothesis  that  the  true 
man  of  science  shows  the  creative  power  which  makes  him  and 
the  poets  brothers.  His  must  be  a  sensitive  soul,  ready  to 
vibrate  to  Nature's  touches.  Before  the  dull  eye  of  the  ordi- 
nary mind  facts  pass  one  after  the  other  in  long  procession, 
but  pass  without  effect,  awakening  nothing.  In  the  eye  of  the 
man  of  genius,  be  he  poet  or  man  of  science,  the  same  facts 
light  up  an  illumination,  in  the  one  of  beauty,  in  the  other  of 
ti-uth;  each  possesses  a  responsive  imagination.  Such  had 
Bernard,  and  the  responses  which  in  his  youth  found  expres- 
sion in  verses,  in  his  maturer  and  trained  mind  took  the  form 
of  scientific  hypothesis. 

That  Bernard  well  understood  the  value  of  imagina- 
tion in  research  and  also  its  dangers  is  well  shown  by  his 
admirable  and  memorable  advice  to  his  pupils : 

Put  off  your  imagination  as  you  take  off  your  overcoat  when 
you  enter  the  laboratory;  but  put  it  on  again,  as  you  do  your 
overcoat,  when  you  leave  the  laboratory.     Before  the  experi- 

16 


ment  and  between  whiles,  let  your  imagination  wrap  you 
round;  put  it  right  away  from  yourself  during  the  experi- 
ment itself,  lest  it  hinder  your  observing  power. 

The  dramatic  and  poetic  instincts  were  strong  in  Ber- 
nard. He  composed  a  vaudeville  comedy  called  "The 
Eose  of  the  Rhone,"  and  later  a  metrical  tragedy  which 
he  altered  to  a  prose  drama.  But  the  love  of  analysis 
and  of  original  research  triumped  over  these  esthetic 
tendencies  of  Bernard's  nature,  and  in  the  reserved  and 
inhibited  personality  and  somewhat  cold  intellectuality 
of  his  maturer  years  it  was  not  always  easy  to  detect 
this  underlying  esthetic  and  emotional  trait.  His  mar- 
ried life  did  not  bring  him  happiness,  as  his  wife  sought 
display  and  material  successes  and  was  unable  to  under- 
stand the  purity  of  purpose  from  which  he  never  swerved 
in  the  long  career  to  which  physiology  owes  so  great  a 
debt. 

Let  us  dow  bring  to  your  attention  some  features  of 
the  mental  life  of  another  great  physiologist,  Hermann 
von  Helmholtz,  representing  a  very  different  phase  of 
physiology  from  that  developed  by  Bernard.  Bernard, 
though  accomplished  as  a  morphologist  and  skilled  in 
mechanical  physiology,  leaned  strongly  to  the  chemical 
side.  He  was  essentially  the  animal  experimentalist. 
Mathematics  played  only  the  most  simple  role  in  his 
researches.  Helmholtz,  on  the  other  hand,  approached 
physiology  on  its  physical  side,  and,  one  may  remark  in 
passing,  with  a  quality  and  amplitude  of  success 
unequalled  before  or  since.  He  used  the  higher  mathe- 
ni;iti<-  constantly  and  they  proved  keen  tools  in  his 
hands.     Although   an   experimentalisl    of  the  very  first 

17 


order,  Helmholtz  was  not  an  animal  experimenter  except 
in  a  very  limited  way,  the  nature  of  his  themes  making 
vivisection  for  the  most  part  unnecessary. 

Even  as  a  child  the  mind  of  Helmholtz  was  unconven- 
tional and  inquiring,  bent  on  understanding  what  was 
going  on  about  him.  The  boy  cut  his  own  path  through 
the  mazes  of  unassimilable  educational  offerings.  His 
tastes  were  definite.  He  obtained  notions  of  geometry 
from  the  blocks  with  which  he  played,  surprised  his 
mother  by  experimenting  on  her  linen  with  acids,  made 
telescopes  with  spectacle  lenses,  read  books  on  physics 
and  enjoyed  greatly  his  walks  in  the  country.  At  the 
university  he  assimilated  ideas  with  great  ease  and 
showed  an  increasing  interest  in  physics,  which  he 
wished  to  follow  as  a  profession.  But  his  prudent  father 
urged  him  to  study  medicine  as  a  surer  means  of  liveli- 
hood. And  most  fortunate  it  was  for  medical  science 
that  the  gifted  young  man  was  willing  to  take  up  medi- 
cal studies,  for  there  arose  in  him  a  deep  interest  in  the 
problems  of  physiology,  destined  to  bear  rich  fruit.  The 
duties  of  an  army  surgeon  took  only  part  of  his  time  and 
the  rest  he  gave  to  physics.  His  original  researches 
began  at  the  age  of  21  and  continued  through  a  long 
lifetime,  covering  an  extraordinary  range  of  topics  in 
an  original  and  masterly  way.  Helmholtz  contributes  to 
minute  anatomy,  lays  the  foundations  of  physiological 
optics  and  acoustics  (with  all  that  this  means  for 
esthetics,  psychology  and  metaphysics),  gives  to  medi- 
cine the  specific  and  golden  gift  of  the  ophthalmoscope, 
enriches  physics  with  an  imperishable  statement  of  the 
doctrine  of  the  conservation  of  energy  and  with  original 

18 


studies  on  vortex  motion,  on  hydrodynamics,  on  electro- 
dynamics, on  dynamics,  on  meteorological  physics.  He 
broadens  chemical  theory  by  the  influence  of  his  vortex 
motion  hypothesis  and,  in  a  somewhat  incidental  way, 
brings  new  theoretical  conceptions  into  the  realm  of 
pure  mathematics.  As  students  of  the  psychical  forces 
that  have  fertilized  modern  medicine  it  is  interesting  for 
us  to  note  that  Helmholtz  disclaimed  any  intention  to 
be  practical  in  his  work.  If  the  themes  that  happened  to 
absorb  his  attention  led  to  practical  and  humanely 
useful  results,  he  was  pleased;  but  he  seldom  pursued  a 
practical  aim  simply  because  of  its  utility.  He  chose 
his  themes  because  they  promised  to  be  intellectually 
satisfying,  giving  little  heed  to  the  nature  of  the  prob- 
able outcome.  He  framed  his  experiments  so  that 
Xature  would  have  to  answer  "Yes"  or  "No"  to  his 
questions,  thus  furnishing  him  with  definite  results. 

The  story  of  the  invention  of  the  ophthalmoscope 
illustrates  the  mental  processes  of  Helmholtz  in  working 
out  an  idea.  He  did  not  set  out  to  devise  an  instrument 
for  studying  the  retina  and  the  ocular  refraction,  but  as 
he  proceeded  these  important  possibilities  ripened  into 
definite  objects.    He  says : 

I  was  endeavoring  to  explain  to  my  pupils  the  emission  of 
reflected  light  from  the  eye,  a  discovery  made  by  Brlicke,  who 
would  have  invented  the  ophthalmoscope  had  he  only  asked 
himself  how  an  optical  image  is  formed  by  the  light  returning 
from  the  eye.  In  his  research  it  was  not  necessary  to  ask  it, 
but  had  he  asked  it,  he  was  just  the  man  to  answer  it  as 
quickly  at  I  did,  and  to  invent  the  instrument.  I  turned  the 
problem  over  and  over  t<>  ascertain  the  simplest  way  in  which 
to  demonstrate  the  phenomenon  to  my  students.     It  was  also 

10 


a  reminiscence  of  my  days  of  medical  study,  that  ophthal- 
mologists had  great  difficulty  in  dealing  with  certain  cases  of 
eye  disease,  then  known  as  black  cataract.  The  first  model 
was  constructed  of  pasteboard,  eye  lenses,  and  cover-glasses 
used  in  the  microscopic  work.  It  was  at  first  so  difficult  to 
use  that  I  doubt  if  I  should  have  persevered,  unless  I  had  felt 
that  it  must  succeed;  but  in  eight  days  I  had  the  great  joy 
of  being  the  first  who  saw  before  him  a  human  retina. 

The  basis  for  this  invention  was  Helmsholtz's  knowl- 
edge of  the  anatomy  of  the  eye,  his  mastery  of  physio- 
logical optics,  his  experimental  ability,  and,  as  stated 
in  his  own  language,  his  wise  to  devise  an  improved 
method  of  demonstrating  a  somewhat  obscure  phe- 
nomenon to  his  students.  Modesty  and  generous 
impulse  made  Helmholtz  say  that  Brucke  could  equally 
well  have  invented  the  ophthalmoscope  had  he  only 
asked  himself  how  an  optical  image  is  formed  by  the 
light  returning  from  the  eye.  I  doubt  if  it  could  be 
successfully  contended  that  Briieke's  actual  information 
about  the  eye  was  less  than  Helmholtz's.  Helmholtz 
himself  says  that  Brucke  "was  just  the  man"  to  make 
the  invention,  and  by  this  he  must  refer  to  equipment  in 
knowledge.  In  what,  then,  did  Helmholtz  excel  Brucke  ? 
I  would  answer,  in  creative  fancy,  in  imagination.  The 
controlled  play  of  fancy,  using  the  facts  of  the  case  for 
its  playground,  is  what  made  Helmholtz  see  the  possi- 
bilities and  sec  them  so  clearly  as  also  to  make  it  appear 
worth  while  to  put  energy  into  the  effort  to  see  the 
retina. 

It  would  be  easy  to  multiply  examples  of  the  almost 
playful  way  in  which  Helmholtz  utilized  the  children  of 
his  rich  fancy  to  extend  the  bounds  of  scientific  knowl- 

20 


edge.  The  ease  with  which  he  made  his  intellectual 
progress  is  one  of  the  most  striking  features  of  his  won- 
derfully creative  career.  Often  on  solitary  walks  in  the 
country  he  experienced  ideas  that  seemed  to  clarify 
refractory  problems.  From  the  great  wealth  of  his 
impressions  and  associated  ideas,  arising  through  the 
operation  of  active  fancy  or  imagination,  there  seems  to 
have  been  a  process  of  controlled  selection  and  rejection 
by  which  the  finished  products,  the  great  ideas,  were 
built  up — a  conscious  selection  not  without  analogies  to 
natural  selection  in  the  upbuilding  of  the  physical 
machinery.  In  the  entire  list  of  the  masters  of  medicine 
I  think  there  has  been  only  one  mind  that  can  be 
regarded  as  belonging  on  the  same  lofty  level  as  that  of 
Helmholtz,  in  respect  to  controlled  yet  expansive  powers 
of  imagination  combined  with  the  energy  of  performance 
and  the  technical  training  necessary  to  apply  those 
powers.  The  intellect  of  Pasteur,  and  his  alone,  has 
revealed  associative  power  and  logical  sequences  of 
thought  culminating  in  discoveries  fairly  comparable  to 
those  of  Helmholtz  in  respect  to  the  depth  of  their 
psychical  basis.  And  it  is  probably  no  accident  that  the 
two  greatest  minds  in  medicine  have  entered  it  on  the 
streams  of  pure  science,  Helmholtz  as  the  biological 
physicist,  Tasteur  as  the  biological  chemist. 

As  a  human  being  Helmholtz  takes  rank  with  the 
noblest  of  men.  Considerateness  for  others  and  a  will- 
ingness to  help  worthy  persons  were  prominent  charac- 
teristic. He  had  a  calm  self-control  which  still  left 
him  QAtnral  and  simple  in  human  relations,  although 
tdi-  fine  dignit]  served  Be  ;i  check  to  the  approaches  of 

21 


shallow  and  trivial  people.  Helmholtz  was  an  idealist 
of  the  purest  type,  and  never  permitted  personal  inter- 
est to  interfere  with  his  best  aims  as  a  student  of  science. 
His  was  a  poetic  nature,  apt  in  versification  and  in 
music,  yet  with  an  intellect  so  searching  that  he  was  not 
entirely  satisfied  by  esthetic  feeling  and  phantasy,  but 
sought  also  to  understand  them.  Modesty  was  one  of 
his  greatest  charms,  and  this  quality  was  attractively 
seen  in  the  sentiment  which  he  expressed  on  being 
awarded  the  von  Graefe  medal  in  recognition  of  his 
services  to  medicine  through  the  invention  of  the 
ophthalmoscope : 

Let  us  suppose  that  up  to  the  time  of  Phidias  nobody  has 
had  a  chisel  sufficiently  hard  to  work  on  marble.  Up  to  that 
time  they  would  only  mold  clay  or  carve  wood.  But  a  clever 
smith  discovers  how  a  chisel  can  be  tempered.  Phidias  rejoices 
over  the  improved  tools,  fashions  with  them  his  god-like 
statues  and  manipulates  the  marble  as  no  one  has  ever  before 
done.  He  is  honored  and  rewarded.  But  great  geniuses  are 
modest  just  in  that  in  which  they  most  excel  others.  That 
very  thing  is  so  easy  for  them  that  they  can  hardly  under- 
stand why  others  cannot  do  it.  But  there  is  always  associated 
with  high  endowments  a  correspondingly  great  sensitiveness 
for  the  defects  of  one's  own  work.  Thus,  says  Phidias  to  the 
smith,  "Without  your  aid  I  could  have  done  nothing  of  that; 
the  honor  and  glory  belong  to  you."  But  the  smith  can  only 
answer  him,  "But  I  could  not  have  done  it  even  with  my 
chisels,  whereas  you,  without  my  chisels,  could  at  least  have 
molded  your  wonderful  works  in  clay;  therefore  I  must  decline 
the  honor  and  glory,  if  I  will  remain  an  honorable  man."  But 
now  Phidias  is  taken  away,  and  there  remain  his  friends  and 
pupils — Praxiteles,  Paionios,  and  others.  They  all  use  the 
chisel  of  the  smith.  The  world  is  filled  with  their  work  and 
their  fame.  They  determine  to  honor  the  memory  of  the 
deceased  with  a  garland  which  he  shall  receive  who  has  done 

22 


the  most  for  the  art,  and  in  the  art,  of  statuary.  The  beloved 
master  has  often  praised  the  smith  as  the  author  of  their 
great  sucess,  and  they  finally  decide  to  award  the  garland  to 
him.  "Well,"  answers  the  smith,  "I  consent;  you  are  many, 
and  among  you  are  clever  people.  I  am  but  a  single  man. 
You  assert  that  I  singly  have  been  of  service  to  many  of  you, 
and  that  many  places  teem  with  sculptors  who  have  decked 
the  temples  with  divine  statutes,  which,  without  the  tools  that 
I  have  given  you,  would  have  been  very  imperfectly  fashioned. 
I  must  believe  you,  as  I  have  never  chiseled  marble,  and  I 
accept  thankfully  what  you  award  to  me,  but  I  myself  would 
have  given  my  vote  to  Praxiteles  or  Paionios." 

If  we  turn  now  to  Helmholtz's  great  contemporary, 
Louis  Pasteur,  we  discern  many  points  of  resemblance 
in  the  mental  endowments  and  in  the  careers  of  these 
two  superlatively  eminent  masters  of  medical  science. 
Pasteur,  like  Helmholtz,  was  greatly  helped  in  early 
life  by  the  patient  guidance  of  earnest  and  capable 
parents,  and,  like  him,  showed  a  strong  interest  in 
poetry  and  art,  the  portraits  made  by  Pasteur  during  his 
teens  showing  unmistakable  artistic  talent.  Pasteur's 
considerable  aptitude  for  mathematics  developed  later 
than  tbat  of  Helmholtz  and  was  of  a  less  original  sort, 
yet  served  him  well,  especially  in  his  earlier  researches. 
Both  men  were  endowed  with  phantasy  and  associative 
power  of  the  highest  order,  but,  while  Helmholtz  seldom 
departed  from  the  path  of  strict  logical  development  of 
his  ideas,  Pasteur,  with  his  more  impetuous  nature, 
-ometimes  permitted  himself  to  make  speculative  excur- 
sions of  a  more  random  kind.  Both  found  their  great- 
est enjoyment  in  dealing  with  the  development  of  gen- 
eral ideas,  but  Pasteur,  on  realizing  his  power  to  help 
mankind  through  his  discoveries,  deliberately  turned  his 

28 


rare  gifts  to  the  solution  of  practical  problems  in  medi- 
cine, whereas  Helmholtz  was  satisfied  to  continue  to 
build  the  foundations  for  the  physiology  of  the  sense 
organs  and  for  a  better  psychology  and  metaphysics.  It 
is  very  noteworthy  that  both  Helmholtz  and  Pasteur 
were  deeply  influenced  in  their  outlook  by  certain  con- 
ceptions of  wide  applicability.  Helmholtz  learned  from 
his  great  master,  Johannes  Miiller,  to  attach  great 
importance  to  the  principle  of  the  specificity  of  nerves — 
that  is,  the  doctrine  which  teaches  that  nerves  of  special 
sense,  as  the  optic  or  acoustic  nerves,  however  stimu- 
lated, respond  with  a  quite  specific  reaction,  with  sensa- 
tions of  light  or  sensations  of  sound,  respectively.  This 
principle  guided  Helmholtz  not  alone  in  his  studies  of 
the  physiology  of  the  special  senses,  but  in  his  philo- 
sophical attitude,  which  brought  him  into  collision  with 
the  widely  accepted  metaphysics  of  Kant.  On  the  other 
hand,  Pasteur's  scientific  and  philosophical  thought  was 
influenced  definitely  and  profoundly  by  the  conception 
of  molecular  asymmetry  in  nature.  His  interest  in  this 
subject  was  awakened  by  the  study  of  the  salts  of  tar- 
taric acid,  which  culminated  in  1848  with  the  famous 
discovery  that  the  optically  indifferent  or  racemic  tar- 
taric acid  crystallizes  into  equal  quantities  of  the  ordi- 
nary dextrorotary  tartaric  acid  and  of  the  newly  recog- 
nized levorotary  tartaric  acid.  It  was  Pasteur's  interest 
in  the  problem  of  molecular  asymmetry,  and  especially 
certain  theoretical  notions  on  which  we  need  not  linger 
here,  that  induced  him  to  experiment  on  the  action  of 
micro-organisms  on  racemic  ammonium  tartrate,  with 
the  striking  result  that  the  living  beings  converted  the 

24 


optically  indifferent  solution  of  salts  into  a  levorotary 
solution.  This  showed  that  the  dextrorotary  constituent 
of  the  indifferent  raceniic  tartrate  had  been  assimilated 
by  the  micro-organisms,  while  the  levorotary  constituent 
was  unaffected.  I  emphasize  these  studies  of  Pasteur's 
because  they  were  what  excited  his  interest  in  the  then 
obscure  problem  of  fermentation,  which  in  turn  led  him 
to  take  up  those  studies  of  the  causation  of  disease  by 
micro-organisms  and  those  researches  on  immunity 
which  have  revolutionized  the  entire  science  and  art  of 
medicine.  To  do  anything  like  justice  to  these  extraor- 
dinarily fertile  and  original  researches  of  Pasteur  is 
wholly  out  of  question  here.  I  can  merely  direct  your 
attention  to  the  researches  which  in  the  fullest  way 
exemplify  Pasteur's  gift  of  imagination  and  power  of 
experimental  control.  There  are  six  studies  or  groups 
of  studies  whose  histories  exhibit  Pasteur's  genius  at  its 
best — the  research  on  the  tartrates,  the  investigations  on 
fermentation,  the  inquiry  into  the  causes  of  the  silk- 
worm disease,  and  the  methods  of  its  eradication,  the 
research  on  chicken  cholera  and  immunity  to  it,  the 
research  on  anthrax,  with  the  extraordinarily  dramatic 
scenes  attending  the  public  test  of  the  immunization 
methods,  and  finally  the  masterly  researches  on  hydro- 
phobia. People  have,  in  general,  been  perhaps  most 
impressed  by  the  researches  on  hydrophobia.  Here  Pas- 
teur dealt  intimately  with  a  disease  affecting  man.  The 
orrible  effects  of  rabies  on  liuman  personality,  the  pub- 
lish of  the  ftret  daring  attempts  at  prevention  by  the 
•  ,'i  attenuated  virus,  the  personal  activity  and  earn- 
estness of  Pas-t '-u r  in  lln-v  lium.ui  <  .|i<iiinents,  the  cir- 

20 


cumstance  that  the  rabic  virus  was  an  invisible  foe  of 
unknown  nature — all  these  features  combined  to  give  to 
these  studies  a  greater  prominence  than  was  accorded 
other  Pasteurian  investigations  of  equal  or  perhaps  even 
greater  merit  from  the  standpoint  of  originality  and 
constructive  intellect. 

In  all  these  different  groups  of  researches  were  dis- 
played the  most  active  powers  of  associative  thought  and 
phantasy,  the  most  admirable  capacity  for  self-criticism. 
As  Pasteur  made  his  publications  in  a  terse,  compact 
style,  we  cannot  always  reconstruct  his  logical  processes 
by  reading  them.  His  method  of  thought  and  procedure 
were,  however,  well  known  to  his  colleagues,  with  whom 
he  loved  to  discuss  his  ideas  and  plans  of  experiments. 
They  found  him  spirited,  fertile  and  imaginative  in  his 
conceptions,  frankly  communicative,  generous  in  giving 
help  and  wholly  absorbed  in  his  work.  Like  many 
intensely  serious  men,  Pasteur  lacked  somewhat  the 
sense  of  humor.  His  feelings  of  partisanship  were  so 
strong  that  he  could  never  overcome  his  resentment 
toward  Germany,  and  he  permitted  this  to  color  even  his 
relations  with  German  scientific  workers.  Yet  one 
should  dwell  but  lightly  on  these  slight  imperfections 
in  a  nature  of  such  great  gifts  and  such  lofty  and  unsel- 
fish purpose. 

At  the  time  when  Pasteur  was  beginning  his  research 
on  anthrax,  a  young  student  of  medicine  at  the  Uni- 
versity of  Strassburg,  Paul  Ehrlich,  was  laying  the 
foundations  for  that  uniquely  fertile  and  versatile  career 
of  medical  research  which  has  made  him  the  most  origi- 
nal and  picturesque  of  living  investigators  of  medical 

26 


science.  Although  at  this  time  Ehrlich  was  especially 
under  the  direction  of  the  anatomist,  Waldeyer,  he  rap- 
idly developed  a  capacity  for  chemistry  which  was  a  sur- 
prise both  to  himself  and  to  the  chemist,  Adolf  von 
Beyer,  whose  lectures  had  been  systematically  cut  by  the 
gifted  but  unconventional  student.  For  unconventional 
he  then  was  and  ever  has  been,  neglecting  what  he  did 
not  like  and  throwing  himself  with  fervor  and  intense 
energy  into  the  solution  of  the  themes  that  attracted 
him.  From  the  outset  it  was  clear  that  Ehrlich  would 
make  a  career  as  an  experimental  investigator.  Much 
of  the  time  he  was  supposed  to  spend  in  taking  the 
usual  medical  courses  he  devoted  to  experiment.  When 
Eobert  Koch  was  shown  through  the  laboratory  at 
Breslau  by  one  of  the  professors  his  attention  was  called 
to  a  young  student  working  at  a  desk  covered  with 
bottles  of  dyestuffs.  "There  is  our  little  Ehrlich,"  said 
the  professor;  "he  is  a  first-rate  stainer  of  tissues,  but 
he  will  never  pass  his  examinations."  The  prediction 
about  the  examinations  came  perilously  near  fulfilment ; 
Ehrlich  made  bad  flunks  and  it  is  hinted  that  he  would 
never  have  received  his  degree  had  not  he  made  a  dis- 
covery— namely,  the  existence  of  the  peculiar  type  of 
leucocyte  which  is  known  to  us  as  the  "plasma-cell." 
The  faculty  reasoned  that  it  would  be  improper  to  keep 
so  promising  and  original  a  worker  indefinitely  in  an 
undergraduate  position,  and  it  is  suspected  that  they 
mitigated  the  rigor  of  the  examinations  in  order  to 
relieve  their  own  embarrassment. 

A  noteworthy  example  of  Ehrlich'!  free-lance  method 
is  Been  in  his  peculiar  way  of  working  at  chemical  prob- 

27 


lems.  Though  a  highly  accomplished  organic  chemist, 
both  as  to  theory  and  a  singularly  rich  acquaintance 
with  the  properties  of  substances,  Ehrlich  rarely  uses 
any  but  the  simplest  methods  and  quite  refuses  to  work 
quantitatively.  His  personal  experiments  are  almost 
exclusively  test-tube  experiments,  most  ingeniously  con- 
trived to  yield  a  rich  fund  of  knowledge.    He  says : 

For  the  pure  chemist,  who  proceeds  analytically  or  syn- 
thetically, my  way  is  only  an  unending  pons  asinorum.  The 
chemist  starts  from  two  substances,  a  and  6,  both  of  which  he 
knows,  and  by  synthesis  derives  substance  c.  Through  this 
procedure  a  sure  insight  into  the  nature  of  the  process  becomes 
possible.  This  is  exactly  as  if  one  drew  a  circle  with  the 
calipers.  On  the  other  hand,  one  may  define  a  circle  by  means 
of  a  large  number  of  tangents,  and  the  chemistry  which  I 
practice  is  a  kind  of  tangent  chemistry.  Through  my  school- 
ing in  this  tangent  chemistry  I  have  had  a  great  advantage  in 
dealing  with  immunity  problems.  If  one  cannot  define  chem- 
ically the  components  entering  into  action,  as  is  frequently 
the  case  in  immunity  problems  (for  example  toxin  and  anti- 
toxin) one  cannot  draw  the  circle  in  the  usual  chemical  way 
and  the  nature  of  the  reaction  process  must  remain  a  closed 
book.  But  for  one  who  has  worked  for  decades,  as  I  have  done, 
at  tangent  chemistry,  the  task  is  no  longer  so  difficult;  and  I 
think  that  in  this  way,  through  the  recognition  of  toxoids  and 
their  quantitative  formation  from  toxins,  I  have  succeeded  in 
correctly  bringing  out  the  two  functional  groups,  the  toxo 
phore  and  the  haptophore,  which  indeed  furnish  us  with  the 
key  to  the  en+ire  doctrine  of  immunity. 

Ehrlich's  dominant  interests  during  the  student  days 
were  histology  and  chemistry,  but  his  attitude  toward 
these  subjects  was  even  then  highly  individual,  original 
and  laden  with  the  dynamic  spirit — the  spirit  that  seeks 
to  gain  a  conception  of  what  goes  on  in  the  living  cells. 

28 


Throughout  his  career  Ehrlich  has  sought  to  use  his 
knowledge  of  histology  and  of  chemistry  to  gain  light  on 
the  processes  of  life.  The  clarity  of  his  visual  percep- 
tions and  the  tenacity  of  his  visual  memories  have 
enabled  him  to  cultivate  a  sort  of  chemistry  peculiarly 
suited  to  this  aim.  Ehrlich  early  recognized  that  he  had 
a  peculiar  gift  of  being  able  to  recall  and  represent  men- 
tally the  constitution  of  a  large  variety  of  substances 
and  with  little  effort  to  picture  vividly  their  interac- 
tions. He  definitely  states  that  he  considers  this  ehemi- 
coplastic  memory  his  greatest  scientific  endowment,  and 
it  is  clear  that  the  long  line  of  his  investigations  is 
founded  on  this  faculty  and  on  his  taste  for  rational 
therapeutics.  Like  Helmholtz  and  Pasteur,  Ehrlich  has 
been  guided  in  his  experiments  by  certain  well-defined 
general  conceptions.  The  most  important  of  these  in 
Ehrlich's  case  is  the  idea  that  the  living  cells  have  many 
different  kinds  of  definite  chemical  affinities,  by  virtue 
of  which  they  are  able  to  enter  into  combination  with 
some  compounds  and  not  with  others.  This  idea  is  at 
the  foundation  of  Ehrlich's  well-known  researches  on  the 
basophilia  acidophilic  and  neutrophilic  leucocytes,  on  the 
distribution  of  dyestuffs  in  the  so-called  "intravital" 
staining,  on  the  cell  affinities  of  the  different  alkaloids, 
on  the  side-chain  theory  of  immunity  and  the  measure- 
ment of  the  strength  of  antitoxin,  and  on  the  organic 
chemical  compounds  of  arsenic  in  relation  to  the  try- 
panosomes  of  the  sleeping-sickness. 

The  recital  of  Ehrlich's  achievements  in  medicine 
would  demand  a  voluminous  space,  for  his  activities  have 
been  intense  and  raried.    The  pharmacological  studies, 


the  work  on  immunity  in  its  different  phases  (including 
the  action  of  hemolysins),  the  experimental  studies  on 
carcinoma — each  of  these  deserve  the  most  careful  study, 
not  merely  because  of  actual  results  gleaned,  but  on 
account  of  the  luminous  ingenuity  of  the  methods 
employed. 

It  is  in  the  field  of  immunity  that  Ehrlich  has  won 
his  brightest  laurels.  The  discovery  that  vegetable 
poisons  like  abrin  and  ricin  excite  antitoxicity,  the 
development  of  a  method  of  measuring  the  activity  of 
the  diphtheria  antitoxin — a  standard  method  the  world 
over — the  extremely  ingenious  studies  of  hemolysins, 
the  recognition  of  the  laws  of  transmission  of  immunity 
from  mother  to  child,  and  the  discovery  of  immunity 
in  trypanosomes  exposed  to  the  action  of  arsenical 
poisons,  are  all  contributions  of  far-reaching  import. 
And  cementing  all  Ehrlich's  special  investigations  of 
immunity,  relating  them  also  with  his  work  on  the  dis- 
tribution of  dyestuffs,  alkaloids  and  nutritive  materials 
generally,  stands  the  famous  "side-chain"  theory.  This 
bold,  elaborate  and  refined  hypothesis  of  the  nature  of 
immunity,  this  offspring  of  rich  phantasy  and  fertile 
experimentation,  was  long  the  source  of  discord  and 
strife  among  bacteriologists  and  pharmacological  the- 
orists. At  the  height  of  the  controversy  Ehrlich  once 
remarked :  "They  are  shooting  into  my  antitoxin  tower 
and  I  will  reply  vigorously."  To-day  a  welcome  peace — 
perhaps  merely  a  truce — has  succeeded  the  sometimes 
heated  contest,  and  only  an  occasional  stray  shot  is 
heard.  However  widely  the  rival  camps  may  disagree 
on  certain  points,  there  seems  now  to  be  a  common 

30 


ground.  The  centrally  emergent  conception  in  immun- 
ity appears  to  be  the  existence  of  a  specific  binding  or 
anchoring  avidity  between  the  immunity-excitant  or 
antigen  and  certain  substances  belonging  to  the  living 
cell — the  so-called  receptors.  This  conception  and  the 
extensions  that  follow  from  it — including,  for  example, 
the  now  familiar  view  that  the  antitoxin  freed  in  the 
blood  represents  excessively  multiplied  receptors  disen- 
gaged from  the  stimulated  cells — are  peculiarly  original 
with  Ehrlich.  His  mind  reached  this  central  idea, 
because  it  is  a  mind  beset  by  chemical  phantasy,  a  mind 
seeking  to  explain  all  biological  phenomena  in  medicine 
by  means  of  chemical  principles.  In  the  special  case  of 
the  side-chain  theory,  Ehrlich's  intimate  knowledge  of 
the  chemical  and  biological  properties  of  the  dyestuffs 
played  a  very  large  part,  and  it  should  be  noted  that 
the  theory  is  in  this  sense  a  hybrid,  that  it  originates  not 
from  a  purely  chemical  conception,  but  from  a  chemical 
and  a  biological  idea.  Slowly  that  theory  grew  to  its 
present  full  proportions  and  its  somewhat  bewildering 
intricacies  of  superstructure.  In  this  elaborate  form 
there  is  doubtless  much  in  the  hypothesis  that  can  be 
criticized  if  we  turn  to  it  in  the  hope  of  learning  the 
absolute  truth  in  respect  to  immunity.  It  is  perhaps 
just  to  say  that  the  value  of  the  theory  lies  largely  in 
the  fact  that  it  expresses  relationships.  Time  and 
experiment  will  doubtless  mold  it  anew.  But  whatever 
changes  in  form  it  may  suffer,  the  data  collected  by 
Ehrlich  and  correlated  by  him  will  long  remain  a  monu- 
ment to  his  experimental  ;.'< -iiiii.s  and  creative  imagina- 
tion.    And   the  fair-minded  critic  will   remember  the 

31 


great  practical  services  which  this  theory  has  rendered 
and  is  still  rendering  to  medicine,  in  enabling  investi- 
gators to  pursue  their  experiments  in  new  territories  of 
research  in  immunity  by  giving  them  points  of  attack 
and  lines  of  advance.  It  is  stated  by  Wassermann,  the 
discoverer  of  the  serum  reaction  of  syphilis,  that  he 
could  never  have  worked  out  this  biological  reaction 
had  he  not  possessed  the  side-chain  hypothesis  as  a 
guide.  It  seems  clear,  too,  that  the  intelligent  use  of 
this  hypothesis  is  destined  to  aid  us  greatly  in  learning 
something  of  the  seat  and  mode  of  action  of  many 
drugs  of  which  we  now  know  but  little.  And,  again, 
there  are  unmistakable  signs  that  the  side-chain  concep- 
tion will  give  many  a  clue  to  the  understanding  of  the 
nutrition  of  cells. 

Ehrlich's  mind  is  singularly  labile,  playful  and  rest- 
less. It  passes  quickly  and  casually  from  one  subject  to 
another,  yet  without  the  least  confusion.  It  is  always 
on  the  alert,  ready  to  dally  with  a  new  fact  or  a  new 
idea,  in  the  hope  that  it  will  illumine  one  of  the  many 
experimental  interests  with  which  consciousness  ever 
teems.  Ehrlich  reads  medical  literature  rapaciously  but 
selectively,  ignoring  all  but  the  themes  in  which  he  has 
a  special  interest,  as  one  reads  who  reads  for  his  pleas- 
ure and  not  for  duty's  sake.  This  unusual  method  is 
extremely  effective  and  gives  a  highly  serviceable  com- 
mand of  facts  likely  to  be  helpful  in  extracting  from 
Nature  new  facts  by  experiment.  Even  during  holiday 
seasons,  this  spirituelle,  penetrating  mind  knows  no  real 
rest,  for  the  time  is  beguiled  by  the  reading  of  detective 
stories,  even  second-rate  ones,  in  the  hope  of  finding 

32 


some  new  and  complicated  situation,  for  which  an 
ingenious  solution  can  be  invented. 

It  is  a  cheering  sign  of  the  times  that  the  cultivated 
classes  are  beginning  to  recognize  the  essential  role  of 
imagination  in  the  progress  of  the  biological  and  medi- 
cal sciences.  President  Eliot  remarks  that  the  nine- 
teenth century  has  taught  us  that,  on  the  whole,  the  sci- 
entific imagination  is  quite  as  productive  for  human 
service  as  the  literary  or  poetic  imagination.  "The 
imagination  of  Darwin  or  Pasteur,  for  example,  is  as 
high  and  productive  a  form  of  imagination  as  that  of 
Dante,  or  Goethe,  or  even  Shakespeare,  if  we  regard  the 
human  uses  which  result  from  the  exercise  of  imagina- 
tive powers  and  mean  by  human  uses  not  merely  meat 
and  drink,  clothes  and  shelter,  but  also  the  satisfaction 
of  mental  and  spiritual  needs."  The  history  of  medical 
discovery  is  a  long  chain  of  imaginative  experiences 
whose  links  have  been  welded  and  fixed  by  passing 
through  the  fiery  ordeal  of  appeal  to  experimental  tests. 
And  could  we  but  set  forth,  in  fitting  language,  the 
true  story  of  these  mental  experiences,  with  all  their 
vicissitudes  of  hope  and  despair,  success  and  failure, 
we  should  certainly  dispel  for  all  time  the  wide-spread 
notion  that  medical  research  is  a  dry  and  painful  task, 
to  which  only  an  unimaginative  mind  can  turn  with 
satisfaction. 

There  is  a  phase  of  imaginative  thought  and  feeling 
which  expresses  itself  in  a  strong  desire  to  pursue  ideal 
ends,  even  at  the  cost  of  the  ordinary  prizes  of  life, 
wealth,  material  power  and  physical  comfort.  This 
idealism   had  been  a  very  pronounced  attribute  of  the 

88 


great  masters  of  medicine.  In  a  noteworthy  degree 
they  have  all  possessed  it  and  some,  like  Helmholtz  and 
Pasteur,  have  led  lives  of  unpretentious,  simple  self- 
sacrifice  in  admirable  harmony  with  the  illustrious  and 
superlative  service  they  have  rendered  mankind.  This 
idealism,  while  clearly  a  moral  trait  in  the  conventional 
sense,  seems  to  be  the  offspring  of  the  creative  intellec- 
tual attitude  and  especially  of  an  absorption  in  work, 
which  leaves  the  mind  neither  time  nor  inclination  to 
seek  the  petty  advantages  for  which  most  men  at  some 
time  in  their  lives  find  themselves  struggling.  For 
these  reasons,  indifference  to  vulgar  aims  and  aloofness 
from  commonplace  interests  are  apt  to  be  found  where 
there  is  preoccupation  in  productive  work  of  a  high 
order,  whether  this  be  concerned  with  science  or  not. 
But  in  the  medical  sciences  the  rewards  are  so  great,  in 
the  sense  of  personal  satisfaction  from  superior  achieve- 
ment, that  there  is  an  especial  and  peculiarly  potent 
incentive  to  repress  those  exaggerations  of  the  self- 
preservative  instinct  which  show  so  insistently  in  the 
selfish  conduct  of  commonplace  persons.  Yet  I  do  not 
think  that  it  can  be  claimed  that  the  motives  of  even 
the  greatest  masters  of  medicine  have  always  been  purely 
altruistic.  In  the  days  of  struggle  for  recognition, 
during  early  manhood,  there  has  commonly  been  evi- 
dence of  mixed  motives  for  action  even  in  the  case  of  the 
noblest  men;  and  at  this  we  can  hardly  wonder.  Some- 
times the  spirit  of  self-interest  has  been  given  too  free 
a  rein.  When  Behring  patented  the  diphtheria  anti- 
toxin, avowedly  with  the  intention  of  gaining  money  for 
further  research,  he  committed  himself  to  a  dubious 

34 


policy  and  one  that  deprived  many  children  of  the  bene- 
fits of  the  life-saving  discovery  by  raising  the  cost  of  the 
antitoxin  serum  to  a  prohibitive  level.  When  Morton 
found  that  sulphuric  ether  could  be  used  for  purposes  of 
general  anesthesia,  he  had  no  hesitancy  in  trying  to 
secure  for  himself  a  patent  for  his  method.  When  we 
contrast  this  attitude  with  that  of  Helmholtz,  who  gave 
the  ophthalmoscope  to  medicine,  and  of  Pasteur,  who 
freely  gave  his  immensely  valuable  discoveries,  it  is 
hardly  necessary  to  comment  on  the  difference  in  spirit 
that  animated  these  men. 

There  is  a  special  quality  pertaining  to  the  greatest 
masters  of  medicine  which  arrests  our  attention  when 
we  survey  their  life  work.  This  is  the  wonderful  variety 
and  number  of  their  discoveries.  We  are  struck  with 
this  quality  of  productivity  in  the  works  of  Hunter, 
Malpighi,  Johannes  Miiller,  Claude  Bernard,  Helm- 
holtz,  Pasteur,  Koch  and  Ehrlich.  In  some  instances 
the  range  of  topics  is  relatively  narrow,  as  in  the  case  of 
Koch,  or  extraordinarily  wide,  as  in  the  case  of  Helm- 
holtz,  but  in  nearly  all  instances  the  great  masters  have 
been  repeatedly  productive,  and  this  varied  productivity 
on  a  high  plane  is  an  unfailing  mark  of  genius.  On  the 
other  hand,  it  is  necessary  to  recognize  that  very  impor- 
tant discoveries  in  medicine  have  been  made  by  men 
who  once  in  their  lives,  and  once  only,  have  attained  a 
high  level  of  achievement.  There  are  two  examples  of 
this  singularity  in  discovery  which  I  would  bring  par- 
ticularly to  your  notice — one  the  discovery  and  develop- 
ment of  the  antiseptic  method  by  Lister  and  the  discov- 
ery of  genera]  anesthesia  by  Morion. 


When  Lister  visited  Pasteur  in  1865  he  was  much 
impressed  by  the  attitude  of  the  great  master  in  regard 
to  the  wide  part  played  by  micro-organisms  in  fermenta- 
tion and  disease.  As  a  surgeon  he  had  a  deep  interest  in 
the  diseases  of  wounds,  and  the  idea  established  itself  in 
his  mind  that  such  diseases  might  be  due  to  a  kind  of 
fermentation  which  might  be  checked  or  prevented  by 
the  use  of  antiseptics.  This  idea,  worked  out  by  Lister 
with  the  utmost  patience  and  superior  intelligence,  gave 
the  wonderfully  far-reaching  results  with  which  we  are 
all  familiar.  The  important  results  of  Lister's  methods 
are  not  limited  to  the  surgical  diseases  of  human  beings. 
By  making  it  possible  to  experiment  on  animals  in 
wholly  new  ways,  these  methods  have  placed  in  the  hands 
of  the  physiologist  a  powerful  instrument  for  the  exten- 
sion of  medical  and  biological  knowledge  along  most 
significant  lines  of  progress.  We  have,  therefore,  to  con- 
cede that  Lister's  discovery  is  one  of  such  rich  fertility 
as  to  make  it  rank  among  the  great  discoveries  of  medi- 
cine. Yet  it  cannot  be  claimed  that  Lister  was  a  great 
scientist.  In  training,  in  originality,  in  versatility  and 
in  imagination  he  is  far  from  being  the  peer  of  the 
great  masters  of  whom  we  have  spoken.  And  we  see 
here,  again,  that  the  practical  import  of  a  discovery  is 
no  arbitrary  measure  of  the  scientific  attainments  of  the 
discoverer. 

Hardly  less  valuable  an  asset  of  practical  medicine  is 
the  discovery  of  general  anesthesia,  but  it  appears  that 
the  qualities  of  mind  revealed  by  Morton  belong  to  a 
level  less  high  than  those  of  Lister.  Morton  was  an 
alert,  enterprising  young  dentist  in  Boston,  who,  while 

36 


educating  himself  in  medicine,  successfully  practiced 
his  calling  and  invented  an  improved  system  of  dental 
plates.  The  use  of  this  system  required  the  free  removal 
of  carious  and  otherwise  diseased  teeth,  and  this  caused 
great  pain.  To  relieve  this  pain,  Morton  pertinaciously 
sought  an  efficient  anesthetic.  After  many  unsatisfac- 
tory trials  with  different  substances,  he  experimented 
with  sulphuric  ether,  given  him  by  Jackson,  the  profes- 
sor of  chemistry  in  the  Harvard  Medical  School.  In 
1846  he  succeeded  in  demonstrating  the  efficacy  of  sul- 
phuric ether  as  a  general  anesthetic  and  thus  gave  to 
mankind  a  precious,  almost  unequalled  boon. 

This  great  discovery  cannot  be  reckoned  as  one  of 
high  fertility,  since,  aside  from  anesthesia,  it  has  not 
opened  new  lines  of  thought  or  practical  service.  Neither 
can  it  be  said  to  have  sprung  from  a  scientific  mind  of 
exalted  qualities  and  attainments.  It  has  the  earmarks 
of  a  child  of  empiricism.  Morton's  scientific  knowledge 
was  slight,  and  his  mind  had  a  strong  commercial  bent. 
The  singularity  of  his  discovery,  the  only  one  of  his  life, 
points  neither  to  fertility  of  resource  nor  to  lofty  imagi- 
nation, but  rather  to  the  fortunate  combination  of  con- 
ditions under  which  he  insistently  exercised  his  ingenu- 
ity. 

Having  told  you  something  of  the  qualities  distin- 
guishing the  modern  masters  of  medicine,  I  now  ask 
your  permission  to  speak  of  certain  aspects  of  these 
qualities  as  they  seem  related  to  the  career  of  the 
thoughtful  student  of  medicine.  And  first  of  all  1  would 
correct  in  your  mi  rids  any  impression  I  may  have  made 
of  a  discouraging  nature.    Having  drawn  our  examples 

:;7 


of  medical  advance  so  largely  from  the  work  of 
supremely  gifted  men,  workers  in  laboratories,  many  of 
whom  have  not  been  practitioners  of  medicine,  or  have 
only  casually  practiced,  it  may  possibly  appear  that  you 
are  confronted  with  the  paradox  that  an  essential  condi- 
tion of  the  loftiest  success  in  medical  science  is  to  abstain 
from  the  practice  of  medicine.  There  is,  indeed,  a  meas- 
ure of  truth  in  this,  for,  as  I  have  already  tried  to  show 
you,  entire  absorption  in  the  practical  problems  of  medi- 
cine unfits  men  to  pursue  with  the  highest  success  the 
career  of  discovery.  In  this  there  is  naught  of  real  dis- 
couragement, but  only  a  sign  that  the  problems  of  dis- 
ease, as  we  meet  them  by  the  bedside,  are  far  too  com- 
plex to  permit  solution  there.  There  was  a  time  when 
all  medical  discovery  was  based  directly  on  observation 
at  the  bedside.  Then,  with  the  growth  of  anatomy,  the 
invention  of  the  microscope  and  the  coming  of  the  twin 
hand-maids  of  medicine,  physics  and  chemistry,  the  lab- 
oratories spring  into  existence.  Much  there  was  that 
could  be  discovered  only  by  laboratory  methods,  and  so 
it  happened  that  some  men  were  justified  in  working  at 
medicine,  and  able  to  become  masters  of  medicine, 
though  they  scarcely  left  their  laboratories.  But  I 
would  have  you  note  well  that  we  have  now  entered  on 
a  time  when  the  clinics  and  the  laboratories  must  work 
more  and  more  closely  together,  aiding  each  other  at 
every  step  to  bridge  the  wide  chasms  of  our  ignorance. 
And  just  here  lies  one  of  the  greatest  opportunities  for 
the  alert  student  of  medicine,  undergraduate  and  post- 
graduate to  do  something  worth  while.  For  the  prob- 
lems are  so  many,  so  varied  and  so  widely  graded  as  to 

38 


their  difficulties  that  for  almost  every  earnest  student 
there  is  at  hand  a  theme  suited  to  his  powers  and  train- 
ing. 

I  have  intimated  my  belief  that  the  powerful  and  con- 
trolled imagination  is  generally  associated  with  a  strong 
vein  of  idealism.  The  explanation  is  not  remote;  the 
imagination  separates  the  wheat  from  the  chaff  in  the 
realm  of  ideals,  picturing  vividly  what  will  yield  endur- 
ing satisfaction.  In  persons  of  average  capacity  and 
imagination,  idealism  is  more  halting  because  the  per- 
ceptions of  what  is  permanently  worth  while  are  less 
definite  and  carry  less  firm  conviction.  Hence  in  such 
persons  idealism  of  conduct  is  less  spontaneous  and  calls 
for  conscious  effort  to  sustain  it.  It  is,  indeed,  a  qual- 
ity which  may  be  deliberately  cultivated  if  the  germ 
exists  in  the  character. 

"What  I  would  like  particularly  to  impress  on  your 
minds  is  that  without  idealism  of  purpose,  without  the 
willingness  to  make  sacrifices  of  material  comfort  and 
much  that  the  world  overprizes,  the  career  of  the  student 
and  practitioner  of  medicine  is  almost  certain  to  be  piti- 
fully limited  and  mediocre.  He  will  do  well  who  has 
the  character  to  run  his  course  in  a  strong  spirit  of  inde- 
pendence, satisfied  during  the  long  years  of  professional 
preparation  with  the  slender  means  that  permit  the  pro- 
longation of  some  phase  of  the  student  life  long  after 
graduation  from  the  medical  school.  There  is  no  surer 
road  to  hopeless  mediocrity  than  that  which  leads  the 
young  physician  to  assume  an  active  practice  before  he  is 
ripe  for  it.  On  the  other  hand,  the  student  physician 
who   v.ait-    patiently,  year  by  year,  to  strengthen  his 

30 


intellectual  grip  on  the  processes  of  disease,  if  possible 
under  the  guidance  of  some  master  of  medicine,  is  lay- 
ing the  unshakable  foundations  of  a  telling  and  distin- 
guished career.  He  need  have  no  anxiety  as  to  the 
future  either  on  the  score  of  professional  recognition  or 
the  ability  to  earn  a  sufficient  income.  For  the  world 
needs  and  must  ever  seek  the  serious,  well-trained,  ideal- 
istic physician  whose  first  thought  is  to  render  a  high 
grade  of  service.  The  superior  type  of  student  will  not 
dread  the  long  years  of  preparation  in  laboratory  and 
clinic.  He  will  eagerly  seek  them  and  will  count  it  the 
greatest  privilege  of  his  life  to  be  able  to  utilize  and 
develop  his  powers.  The  fascinating  interest  of  his 
problem  and  the  elevation  of  his  ideals  will  keep  him 
buoyant  under  chircumstances  of  discouragement.  If 
he  be  blest  with  a  fair  share  of  imagination  and  ideal- 
ism he  will  never  falter  in  the  struggle  to  make  a  worthy 
career,  for  he  will  know  that  he  is  treading  in  the  foot- 
steps of  the  great  masters  of  medical  science  and  that  in 
doing  so  he  is  helping  to  assuage  human  suffering,  per- 
haps also  to  illuminate  some  of  the  dark  problems  in  the 
baffling  mystery  of  life.  And  in  this  consciousness  will 
he  find  ample  compensation  for  the  self-abnegation 
which  such  a  career  must  necessarily  exact  from  its 
votaries. 

819  Madison  Avenue. 


40 


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